Is Hong Kong iPhone compatible in US (ATT))

If its unlocked, not tied to any carrier, it will work in the U.S.

It won’t connect to the mmwave 5G though, only regular 5G, and will not have warranty in the US, so you will need to take it back to Hong Kong for any repairs or warranty service.

Hello,

That is not a good idea. You should always buy the phone in the country where it will be used for warranty purposes.

Good luck.